1. Field of the Invention
This invention relates generally to field of pressurization systems and in particular to a mixing gas generator pressurization system for liquid propellant pressure-fed rocket systems.
2. Description of the Prior Art
Conventional liquid rocket systems have their propellants stored in tanks at relatively low pressure. Complex turbopump systems are employed to raise the propellants to the high pressure necessary to supply the rocket's combustion chamber. Pressurize-fed rocket systems are much less complex. The propellant storage tanks are pressurized to a high pressure such that the propellents can be directly injected into the rocket's combustion chamber. Normally a high-pressure gas supply is used to pressurize the tanks and expel the propellants. For large pressurize-fed rocket systems, an impracticably large pressurization system would be required to pressurize the main propellant tanks. As a consequence, large liquid propellant rockets invariably use turbopump systems.
A tank pressurization system is needed that can supply sufficient high-pressure gas for pressurize-fed liquid rocket and spacecraft systems at reduced system volume, weight, and pressure storage requirements. The HAN TEAN system of the present invention fulfills these requirements, providing a controlled rate of high-pressure gas free of harmful byproducts.
HAN TEAN is a single liquid propellant containing both an oxidizer and a fuel component. HAN (hydroxyl ammonium nitrate) is the oxidizer and TEAN (triethanol amine nitrate) is the fuel. Both components are salts that are dissolved in water. By volume, HAN TEAN is composed of 60.8% HAN, 19.2% TEAN, and 20.0% water.
HAN TEAN was originally developed by the U. S. Army for regenerative propellant gun applications. See, for example, U. S. Pat. Nos. 5,608,179, 5,014,623, and 4,946,521. HAN TEAN has also been used as a liquid fueled inflator for motor vehicle airbag systems, e.g., U. S. Pat. Nos. 5,060,973 and 5,607,181. Both of these uses essentially employed HAN TEAN as an explosive to rapidly generate large volumes of gas, either to propel an artillery shell out of a gun barrel or to rapidly inflate an air bag.